Clean-out means for grain dryer

ABSTRACT

An improved means for cleaning out the grain that makes its way into the plenum chamber of a grain dryer. The hinged or flexible sheets normally used at the bottom of the chamber are held up in closed position by spring-biased clips which, although readily released by hand, nevertheless hold the sheets in such manner that they are able to support the weight of a man walking on the said sheets.

v U nlted States Patent [151 3,659,351 Alms et a]. [4 1 May 2, 1972 r 541 CLEAN-OUT MEANS FOR GRAIN 3,056,214 10/1962 Andersen; ..34 174 DRYER 998,027 7/l9l 1 Meyer ..34/l 74 UX [72] Inventors: Erhard Alms, .Burrington; James E.

Mhchcn both of Primary Examiner-Frederick L. Matteson 731 Assignee: AFE Industries, Inc., Lake Zurich, 111. Assistant Examiner-Harry Ramey Attorney-Charles F. Voytech [22] Filed: May 4, 1970 [21] Appl. No.: 34,027

[57] ABSTRACT An improved means for cleaning out the grain that makes its way into the plenum chamber of a grain dryer. The hinged or [58] Field Search g2 5 flexible sheets normally used at the bottom of the chamber are held up in closed position by spring-biased clips which, although readily released by hand, nevertheless hold the [56] References Cited sheets in such manner that they are able to support the weight UNITED STATES PATENTS of a man walking on the said sheets.

3,040,443 6/1962 Bo f .,34/ l 74 3 Claims, 5 Drawing Figures P PATENTEDMM 21972 sum 1 UF 2 CLEAN-OUT MEANS FOR GRAIN DRYER This invention relates to grain dryers and to apparatus used to clean out the plenum chamber thereof.

A well-known grain dryer available commercially at the present time is comprised of a double-walled oval-shaped bin into which grain to be dried is placed. The inner wall forms a plenum chamber into which hot air is forced. Both walls are perforated to allow the hot air to pass through the grain. However, small particles of the grain sometimes fall through the perforations of the inner wall into the plenum chamber, and it becomes necessary to clean out these particles to avoid an accumulation of grain at the bottom of the bin which would interfere with the passage of dry air through the lower regions thereof. Lack of sufficient air flow through the grain produces incompletely dried grain, and the grain removed from the dryer therefore is not uniformly dry.

In the past, clean-out of grain has been effected by forming an access opening in the bottom of the plenum chamber and then closing it with hinged plates which are extensions of the plenum chamber wall. In some cases, the plates were left to hang down of their own weight and closed by the pressure of the grain in the bin. This left the gates only partly or imperfectly closed during the drying operation. Since the hot air for drying the grain is supplied by one or more fans which produce a swirl in the plenum chamber, it has been found that this swirl causes the grain to be picked up from any opening in the chamber, such as that formed between the incompletely closed gates and blown into the plenum chamber to increase the amount of unwanted grain therein.

It is an object of this invention to provide improved means for holding in closed position the clean-out gates of a grain dryer.

As a more specific object, this invention has within its purview the provision of a holding means for the clean-out gates of a grain dryer, said holding means comprising a readily releasable clip which when assembled with the gates is strong enough to support a man walking on the gates.

It is also an object of this invention to provide a clip for holding pivoted clean-out gates of a grain dryer in closed position, said clip being readily released without the aid of special tools.

These and other objects of this invention will become apparent from the following detailed description of a preferred form of the invention when taken together with the accompanying drawings in which:

FIG. 1 is an end elevational view in section of a grain dryer in which this invention has been incorporated;

FIG. 2 is an enlarged fragmentary end elevational view in section of the lower portion of the grain dryer showing the clean-out means of this invention in greater detail;

FIG. 3 is a fragmentary side elevational view in section of the lower portion of the grain dryer of FIG. 2 taken along line 33 of FIG. 2;

FIG. 4 is an enlarged end elevational view of a portion of the clean-out means of FIG. 2; and

FIG. 5 is a fragmentary plan view of a clip forming part of this invention as incorporated in the clean-out means of FIG. 2, the view being taken along line 5--5 of FIG. 2.

By way of general description, the preferred form of this invention comprises a series of longitudinally aligned gates located at the bottom of the plenum chamber of a grain dryer, the gates being hinged to the wall defining the plenum chamber. The hinges are horizontally disposed to provide for a downward swing of the gates to dump the accumulated grain from the plenum chamber into the area of the auger used to evacuate the dryer. The gates are formed with longitudinal, downwardly directed flanges at their adjacent sides, and spring-supported U-shaped clips embrace the flanges to hold the gates in elevated position, i.e., in position to close the plenum chamber to the grain in the drying chamber. The geometry of the gates, hinges and clips is such that very little force is required to hold the clips in place, and yet the gates in closed position will support the weight of a man walking thereon. The clips can be readily released from the flanges on the gates, without the use of any tools, to drop the gates'when it is desired to clean out the plenum chamber.

Referring now to the drawings for a detailed description of the invention, a dryer to which the clean-out gates and supports of this invention have been applied is shown in FIG. I. The dryer is shown in section in end elevation and may be of the type disclosed in Arthur E. Andersen, Jr. US. Pat. No. 3,056,214, dated Oct. 2, I962. The dryer shown herein is comprised of spaced oval-shaped inner and outer perforated walls 10 and 11 of sheet metal secured to ribs 12 and 13 form ing a basic frame for the dryer. Said frame includes vertically disposed struts l4 and 15 connected to horizontal braces 16, the whole being mounted on suitable footings l7 and 18.

Inner wall 10 defines a plenum chamber 19 into which heated air is blown by one or more fans 20. The space between walls 10 and 11 constitutes columnar bins 21, 22 which are filled with grain to be dried, by a common input auger 23 at the top of the dryer, and emptied of the dried grain by a common output auger 24 located at the bottom of the dryer. The volume of hot air supplied to plenum chamber 19 is sufficient to create a pressure differential across the columnar bins 21 and 22 so that the hot air passes through perforated wall 10, thence through the grain in bins 21 and 22 to extract moisture from the grain therein, and then out to the atmosphere through perforated wall 11. The air so supplied is agitated by the fans 20 and finds every opening and crevice in wall 10, so that any grain falling into plenum chamber 10 through the perforations in wall 10, or exposed to the air by a crevice in said wall, will be picked up and blown into drifts which then block the passage of air through the wall l0 and interfere with the drying process. 7

Although prior 'dryers have provided gates at the bottom of the plenum chamber to make possible the removal of grain therefrom, such gates did not provide means for tightly closing them and hence required frequent shut-down of the dryer to permit cleaning out of the plenum chamber.

The gates of this invention are shown at 25 in FIG. 1 and in greater detail in FIGS. 2-5. The gates are comprised of substantially rectangular perforated sheets 26 and 27 disposed one on each side of the bottom of plenum chamber 19. Said sheets, in the example illustrated, are approximately 4 feet long, and where the dryer is considerably longer than 4 feet, a series of 4-foot long sheets may be used on each side, said sheets being appropriately overlapped at their adjacent edges to avoid the creation of crevices through which the fan-driven hot air can extract grain and blow it into plenum chamber 10. Each sheet 26, 27 has one longitudinal edge 28, 29, respectively, curled under to pass around a rod 30, 31 which functions as a hinge pin. Each rod is supported from the ribs 12 by eye-bolts 32 through which the rod passes, said eye bolts being appropriately secured to said ribs. The plenum wall 10 terminates on either side of gates 25 adjacent eye-bolts 32 and is formed with a depending longitudinal flange 33 which serves to close as completely as possible the space between wall 10 and sheets 26 and 27.

During normal operation of the dryer, sheets 26 and 27 are held firmly against the bottom of ribs 12 by a series of U- shaped clips 34. To this end, the sides of sheets 26, 27 which are adjacent one another are formed with longitudinal flanges 35, 36 which, when the sheets are in closed position, are parallel with one another and are so spaced as to be embraced by U-shaped clip 34 and bear against the upright sides 37 and 38 of said clip 34. The latter is held up against flanges 35, 36 by a tension spring 39, the ends of which are passed through cotter pins 40 and 41 secured respectively to the bottom of clip 34 and to a horizontal bar 42 bolted or otherwise secured to the adjacent ends of aligned ribs 12.

It may be observed that when the sheets are closed and clip '34 embraces and interlocks with the flanges 35, 36 of said sheets, any tendency of the sheets to swing down to the open position thereof is resisted by the sides 37, 38 of clip 34, and that there is no downward force exerted by the gates upon clip 34 in opposition to spring 39. The latter, therefore, need only be strong enough to support the weight of clip 34 and any grain and air pressure that might be exerted on the clip by grain drifts in the plenum chamber and the air pressure therein. When in closed position, sheets 26, 27 can readily support the weight of a man walking thereon.

To release sheets 26, 27 to clean out plenum chamber 19, each clip 34 is depressed manually against the resistance of spring 39 until sides 37, 38 of clip 34 pass below and are free of flanges 35, 36. The clip is then turned to pass between flanges 35, 36 where the clip is no longer effective to prevent the sheets from swinging down. The latter then fall to the dotted positions shown in FIG. 2. Should the foot of the man operating the gates 25 become wedged between flanges 35, 36 of the sheets while the latter are in raised position, the clips 34 may readily be depressed and turned to release flanges 35, 36 and allow the sheets to fall, thus freeing the man's foot.

It may be observed that grain pressure on the bottom sides of sheets 26, 27 cannot raise the flanges 35, 36 out of clip 34 since such pressure merely serves to hold the sheets against ribs 12, while spring 39 continues to pull upwardly on clip 34 to follow sheets 26, 27.

lt is understood that the foregoing description is merely illustrative of a preferred embodiment of the invention and that the scope of the invention therefore is not to be limited thereto, but is to be determined by the appended claims.

We claim:

1. In combination in a grain dryer having an outer perforate wall, an inner perforate wall spaced from the outer perforate wall and defining a plenum chamber, the space between the inner and outer walls comprising a columnar bin for grain to be dried, means for circulating heated air through the plenum chamber and through said columnar bin, perforate plates at the bottom of the plenum chamber and forming part of said inner wall, means hinging said plates for swinging movement about horizontal axes to provide an opening into said plenum chamber, means for releasably holding said plates with their planes extending substantially parallel with the outer wall, spaced rigid ribs for the inner wall, and means securing said ribs together, said plates extending under said ribs, and said means for releasably holding said plates comprising means interlocking said plates together while said plates bear against the ribs.

2. The combination described in claim 1, said means for releasably holding said plates comprising a clip extending across and around adjacent edges of said plate, and resilient means secured to said clip and urging said clip toward said ribs.

3. The combination described in claim 2, said plates having flanges extending downwardly from adjacent sides thereof, said adjacent edges of said plates being formed at the ends of said flanges, said clip being U-shaped and embracing said flanges, and said resilient means comprising spring means in tension connecting said U-shaped clip and said ribs. 

1. In combination in a grain dryer having an outer perforate wall, an inner perforate wall spaced from the outer perforate wall and defining a plenum chamber, the space between the inner and outer walls comprising a columnar bin for grain to be dried, means for circulating heated air through the plenum chamber and through said columnar bin, perforate plates at the bottom of the plenum chamber and forming part of said inner wall, means hinging said plates for swinging movement about horizontal axes to provide an opening into said plenum chamber, means for releasably holding said plates with their planes extending substantially parallel with the outer wall, spaced rigid ribs for the inner wall, and means securing said ribs together, said plates extending under said ribs, and said means for releasably holding said plates comprising means interlocking said plates together while said plates bear against the ribs.
 2. The combination described in claim 1, said means for releasably holding said plates comprising a clip extending across and around adjAcent edges of said plate, and resilient means secured to said clip and urging said clip toward said ribs.
 3. The combination described in claim 2, said plates having flanges extending downwardly from adjacent sides thereof, said adjacent edges of said plates being formed at the ends of said flanges, said clip being U-shaped and embracing said flanges, and said resilient means comprising spring means in tension connecting said U-shaped clip and said ribs. 